We present several sharp upper bounds and some extension for product operators. Among other inequalities, it is shown that if , are non-negative continuous functions on such then all operator monotone decreasing function we obtain As an application of the above inequality, where, .

We use mixed norm estimates for the spherical averaging operator to obtain some results concerning pinned distance sets.

As an special intuitionistic fuzzy set defined on the real number set, triangular intuitionistic fuzzy number (TIFN) is a fundamental tool for quantifying an ill-known quantity. In order to model the decision maker's overall preference with mandatory requirements, it is necessary to develop some Bonferroni harmonic mean operators for TIFNs which can be used to effectively intergrate the informa...

Addition theorems can be constructed by doing three-dimensional Taylor expansions according to f(r + r) = exp(r · ∇)f(r). Since, however, one is normally interested in addition theorems of irreducible spherical tensors, the application of the translation operator in its Cartesian form exp(x∂/∂x) exp(y∂/∂y) exp(z∂/∂z) would lead to enormous technical problems. A better alternative consists in us...

We present a method for solving the Stokes problem in unbounded domains. It relies on the coupling of the transparent boundary operator and a spectral method in spherical coordinates. It is done explicitly by the use of vector-valued spherical harmonics. A uniform inf-sup condition is proved, which provides an optimal error estimate.